Hello, I m afraid this single piece of information is not enough for a complete answer but I ll do my best to give you the most clear picture I can. HbsAg is the surface antigen of hepatitis B virus. This if found in the blood after the body gets infected with hepatitis B (acute hepatitis). If it is detected for more than 6 months after infection then this is called chronic hepatitis . Chronic hepatitis could be active or inactive (carrier). The active state is the most dangerous one both for you and for the others. Transmission can occur during the carrier state as well. 1 out of 4 carriers develop active chronic hepatitis. If you do not have an active disease then you cannot do much about it (treatment is not indicated). Your girlfriend/spouse can protect herself by immunization, unless she s already infected too. If you need further clarifications on your condition, please ask again, including more information from serologic testing. I hope I ve addressed your concerns! Kind Regards!